Boom angle and radius indicator



April 24, 1945. O NASSET 2,374,298

BOOM ANGLE AND RADIUS INDICATOR Filed Feb. 25, 1943 3 Sheets-Sheet l I N VEN TOR.

ATTORNEYS April 24, 1945. o. N. NASSET BOOM ANGLE AND RADIUS INDICATOR s Sheets-Sheet 2 Filed Feb. 25, 1945 myzaw aa ATTORNEYS April 24, 1945. o. N. NASSET BOOM ANGLE AND RADIUS INDICATOR 5 Sheets-Sheet 3 Filed Feb. 25, 1943 5 Y E N R m A ture of Figures 6, '1 and 8.

Patented Apr. 24, 1945 UNITED STATES PATENT OFFICE BOOM ANGLE AND RADIUS INDICATOR Olaf Niel Nasset, Toledo, Ohio Application February 25,1943, Serial No. 477,119

2 Claims.

My invention relates to cranes, derricks and the like, and has among its objects and advantages the provision of an improved boom position indicator.

An object of my invention is to provide a device v.of the type described wherein novel means are provided for accurately indicating the angle and the distance the center of loading is from the center of rotation of the boom in all positions thereof, so that the loading distance of the boom may be readily determined by a glance at the indicator, in addition to the boom angle, whereby loads carried by the boom may be placed in exact predetermined positions and in which the indicator constitutes an aid which enables the operator to determine the proper boom load in the different positions of the boom.

In the accompanying drawings: 7

Figure 1 'is a diagrammatic elevational view of a conventional crane;

Figure-.2 is an enlarged detail view of a portion of the crane boom and cabin illustrating my invention applied thereto;

Figure 3 is a face view of the housing;

Figure {is moved;

Figure 5 is a transverse sectional view of the indicator dial a similar view with the dials redial housing;

Figures 6 and 7 respectively illustrate a cable guidez. a

Figure 8 is a sectional view-along the line 8-8 of Figure 6; and

Figures 9, 10 and 11 respectively comprising an end view, a top view and a side view in section of a second cable guide coacting with the struc- In the embodiment selected for illustration, the crane iii of Figure 1 includes the usual cabin l2 and boom M. In Figure 2, the boom I4 is pivotally supported at its lowerend on a bracket l6 through the medium of the usual foot pin IS, the bracket it being fixedly secured to the cabin l2 in the customary manner.

To the wall of the cabin i2 is attached a dial housing ,22 placed so as to be in view'of the provided with a pinion'62 meshing with a gear 64 attached to a'shaft 88 rotatably :lourn'aled in the frame members 44. To the shaft 66 is fixedly "connected a boomangle indicating pointer 68.

The gear 60 and the pinion 62 are fixedly related and rotate on a stubshaft Ill attached to one of the frame members 4. Meshing with the gear 60 is .a gear I2 mounted on a shaft 14 rotatably joumaled in the frame members 44 and to which a boom loading center indicating pointer I6 is attached- I prefer to design the drum. with a circumference of four inches and rotating through three complete revolutions in ninety degrees of boom travel. The pinion 58 and the gear 60 have a ratio of three to one. The ratio of the pinion .62 and the gear 84 is four to one. The gears 60 and 12 are of equal diameters.

.The cable 58 passes loosely through an opening 16 in the cup 28, this cup being provided with a boss 18 through which the opening extends.

' An eye 80 is formed on the outer end of the cable crane operator stationed at the control lever 24.

Figures 4 and fi-illustrate the dial housing 22 as comprising a cup-like member 26 fixedly secured to the wall 20 through the medium of bolts 28 ex- This cup is provided with a flange 32 against which is positioned two transparent dial faces 34 and 38 held in place by a bezel 38 secured to the flange 32 by screws 40.

' tending through the bottom 30 of the cup 26.

56 for connection with a turn buckle 82 connected with an eye 84 in the section 86 of the cable 58. This cable passes around a grooved wheel 88 rotatably supported in a bracket 90 formed on a nut 92. This nut is threadedly connected with a short pin 94 extending through an opening 98 in the wall 20. A second nut 88 is threadedly connected with the pin 94 and coacts with the nut 92 to fixedly secure the pin. This pin is provided with a coaxial extension I00, the pin and the extension being provided with a common cable guiding bore I02.

To the boom ll is attached a cable'guide I lil tioned by reason of slots I08 through which are passed fastening bolts I I0 threaded into the boom ll.

Figure 2 illustrates the guide 104 as having an end face H2 terminating on the center line II4 of the boom, with the cable bent about the corner IIS and provided with an eye II8 for the reception of a fastening bolt I20 threaded into the boom I4. The guide I04 has a curvature extending throughout an arc of ninety degrees, and the pin 94 and its extension I are so positioned that the cable 56 will pull straight from the exinstant case being designed for a boom having a loading center of thirty-five feet.

In operation, the drum 54 has three and onehalf wraps of cable 56'thereon when the angle indicating pointer 68 is at the ninety degree graduation on the scale I22. The cable 56 is provided with a stop I26 engaging the boss 18 in the ninety degree position of the pointer 68. As the pointer 68 moves from the horizontal to its vertical positions, the spring 48 rotates the drum 54 to wind the cable thereon. The position of the pointer 88 corresponds at all times to the position of the boom I 4.

A plate I28 is mounted in the cup 28 to mask the mechanism of the indicator from view.

Without further elaboration, the foregoing will so fully illustrate my invention, that others may, by applying current knowledge, readily adapt the same for use under various conditions of service.

I claim:

1. The combination with a support and a vertically movable boom pivotally connected with the support, of a dial housing mounted on the support, a first shaft journaled horizontally in the housing, a drum fixed on said shaft, a pinion fixed on the shaft adjacent the drum, a second shaft rotatably mounted parallel with said first shaft, a gear fixed on said second shaft in mesh with said pinion, a pinion fixed on said second shaft, a third shaft rotatably mounted below and parallel with the second shaft, a gear secured on said third shaft meshing with the pinion on the second shaft, a pointer fixed on the third shaft to indicate the angular position of the boom, a fourth shaft journaled on the housing parallel with the first shaft, a gear fixed on said fourth shaft in mesh with the gear on the second shaft, a pointer fixed on said fourth shaft to indicate the distance of the center of the loading from the centerof rotation of the boom, a quadrant scale on the 'housing in co-operative relation with the angle indicating pointer, a circular scale on the housing in co-operative relation with the loading distance indicating pointer, a cable having winding connection with the drum and operatively connected with a boom, and a spring acting on said drum to resiliently wind the cable thereon and tending to turn the pointers to their zero positions.

2. The apparatus as claimed in claim 1 wherein a member is fixedly connected to the boom having an arcuate guide surface on the top thereof,

means connecting the outer end of the cable to the boom at the inner end of said guide surface, and a wheel mounted on the support over which the cable is trained, said wheel being disposed to drive the cable so that it extends downwardly from the drum and horizontally to and is pulled over the guide surface as the boom is lowered.

OLAF N. NASSET. 

